<p>This paper presents a CFD study of mixed convection within a square enclosure containing a non-Newtonian power-law fluid. The enclosure features insulated top and bottom walls, while the vertical walls are maintained at constant hot and cold temperatures. By adopting a dynamic mesh technique, a slender, rigid, rotating blade placed at the center of the enclosure is implemented to regulate the convective flow in the enclosure. Solution of various governing equations is obtained through the finite element approach within the Arbitrary Lagrangian–Eulerian framework with triangular and quadratic mesh discretization scheme. Variation of non-Newtonian fluids are assumed through the variation of the power-law index (<i>n</i>) and Prandtl number (<i>Pr</i>) which are varied within the ranges (0.6 ≤ <i>n</i> ≤ 1.4) and (1 ≤ <i>Pr</i> ≤ 100) respectively while two key mixed convective parameters such as the Richardson number (<i>Ri</i>) and the Reynolds number (<i>Re</i>) are varied in the range of (0.1 ≤ <i>Ri</i> ≤ 10.0) and (100 ≤ <i>Re</i> ≤ 500), respectively. The system’s characteristics are evaluated qualitatively in terms of streamline and isothermal distribution. Both the heat transfer as well as mechanical performance of the system have been assessed in terms of spatially-averaged Nusselt number and frictional energy consumption for aforementioned variation of system configuration. Obtained results demonstrate enhanced thermal performance with increasing Prandtl number, Richardson number, and Reynolds number particularly the shear-thinning fluids in comparison to shear-thickening and Newtonian fluids. The findings of this study offer valuable insights in modulating non-Newtonian power-law fluids for heat transfer enhancement covering a wide range of industrial applications such as: cooling and shaping of polymers, advanced cooling systems for electronics and batteries.</p>